210021221121 has 4 divisors (see below), whose sum is σ = 280028294832. Its totient is φ = 140014147412.

The previous prime is 210021221083. The next prime is 210021221173. The reversal of 210021221121 is 121122120012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210021221121 - 2⁷ = 210021220993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 210021221121.

It is not an unprimeable number, because it can be changed into a prime (210021241121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35003536851 + ... + 35003536856.

It is an arithmetic number, because the mean of its divisors is an integer number (70007073708).

Almost surely, 2^210021221121 is an apocalyptic number.

It is an amenable number.

210021221121 is a deficient number, since it is larger than the sum of its proper divisors (70007073711).

210021221121 is an equidigital number, since it uses as much as digits as its factorization.

210021221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70007073710.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 210021221121 its reverse (121122120012), we get a palindrome (331143341133).

The spelling of 210021221121 in words is "two hundred ten billion, twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".